The intracellular hematozoa of vertebrates are apicomplexan parasites with a life cycle consisting of 3 major phases: schizogony (asexual), gametogony (sexual), and sporogony (asexual). Most members have heteroxenous life cycles, wherein gametogony and sporogony occur in an arthropod vector and schizogony occurs in the vertebrate host. Leucocytozoon toddi occurs in Falconiformes and Leucocytozoon ziemanni in Strigiformes. Considered nonpathogenic in adult raptors, Leucocytozoon can cause mortality in nestlings. Haemoproteus is generally considered nonpathogenic in raptors; however, there are recent reports of fatalities in owls. Plasmodium is the true malarial parasite of birds and mammals. One species, Plasmodium relictum, is considered pathogenic for raptors. Atoxoplasma (previously Lankesterella) is an avian coccidian with both blood and intestinal stages. Babesia has been reported in raptors and might cause anemia and blindness in young falcons. In this article, advances in hematozoon diagnosis, treatment, and prevention are discussed. Although some hematozoa of raptors are considered nonpathogenic, high parasitemias in peripheral blood could indicate an underlying disease process.

Electroretinography is a noninvasive method of evaluating retinal function, which is especially useful when evaluating patients with cataracts. This study was undertaken to characterize the normal latencies, amplitudes, and presence of oscillatory potentials in the electroretinogram of Hispaniolan Amazon parrots (Amazona ventralis). Six healthy 3-year-old parrots with clinically normal eyes were anesthetized with isoflurane. Electroretinograms were recorded in the light- and dark-adapted states with white light and in the dark-adapted state with white, red, and blue light. Oscillatory potentials were also recorded. The mean latency for the light-adapted a-wave was 11.35 (±1.54) milliseconds and for the light-adapted b-wave was 24.4 (±6.17) milliseconds. The mean amplitude of the light-adapted a-wave was 20.4 (±5.45) μV and of the light-adapted b-wave was 57.34 (±27.82) μV. The mean latency for the dark-adapted a-wave was 12.15 (±1.55) milliseconds and for the dark-adapted b-wave was 29.65 (±3.98) milliseconds. The mean amplitudes of the dark-adapted a-wave and dark-adapted b-wave were 38.61 (±13.44) μV and 129.47 (±26.12) μV, respectively. The oscillatory potentials were composed of 3 or 4 peaks. Variability in latency increased from O1 to O4, and 3 eyes did not have recordable O4. The data showed that the latencies of the a- and b-waves and the amplitudes of the dark-adapted b-waves of Amazon parrots were similar to those of dogs with normal retinas. The light-adapted a- and b-waves of the parrots had greater amplitudes than did the light-adapted a- and b-waves of dogs.

The Cavitron Ultrasonic Surgical Aspirator (CUSA) is an ultrasonically powered aspirator that selectively fragments and aspirates parenchymal tissue while sparing vascular and ductal structures. We evaluated the CUSA and the CO₂ laser for removal of lipomatous masses in 16 budgerigars (Melopsittacus undulatus). With both methods, the level of hemorrhage and length of operating time was acceptable. However, the CUSA, which irrigates and aspirates continuously, provided superior visibility of the surgical field. Results of this study indicate that either the CO₂ laser or the CUSA may be safe and effective in removing lipomas from birds.

The purpose of this study was to determine whether a reduction in dietary iron concentration can result in significant decreases in hepatocellular hemosiderin content in toucans with iron-storage disease. We studied 2 adult toco toucans (Ramphastos toco) previously diagnosed with iron-storage disease. Liver biopsy specimens were taken before lowering dietary iron levels to <100 mg/kg on a dry-matter basis and taken again 8 months later. One bird died from airsacculitis at 12 months, and a postmortem specimen was also analyzed. Computerized image analysis of the specimens showed significant reductions (P < .001) in hepatocellular hemosiderin content over this period. Computerized image analysis is a valid means of quantifying relative iron content in serial liver biopsy specimens and can be used to monitor response to dietary iron reductions in birds with iron-storage disease. The significant relative reduction in hepatocellular iron content in these 2 toucans with iron-storage disease, in response to dietary modification alone, is encouraging. More work is required to determine whether dietary iron levels can be safely reduced still further, as well as whether a greater effect can be obtained by instituting such modifications for other toucans before clinically significant liver damage has occurred.

A 10-year-old, green-cheeked conure (Pyrrhura molinae) was examined because of weight loss and neurologic signs referable to a focal left cerebral lesion. The clinical signs did not improve with treatment, and the animal was euthanatized for humane reasons. A primary brain tumor involving the left cerebrum was found at necropsy. On the basis of histologic morphology and results of immunohistochemical staining of the tumor, the diagnosis was malignant astrocytoma with features of glioblastoma multiforme.